I mostly agree and see where you're coming from but disagree on "bad luck". I consider it an inevitability in today's game. Someone will get injured. Gonzalez will take their place. Where Gonzalez separates himself from someone like, say, Adrianza, is that he can play anywhere. In your scenario, I'd probably agree that it requires a fair amount of "bad luck" to get Adrianza 400 PAs, as it means your middle infield was torn to shreds over the season. But in the case of Gonzalez, it could come in small bursts all over the diamond: 40 PAs in left, 60 PAs at short, 80 PAs at third, etc. Because of Gonzalez' versatility, I don't believe it requires bad luck for him to get a lot of playing time all over the field, all the while replacing someone at neutral or negative WAR value. Starters will get dinged up over the season and having a guy already on the roster to fill in for them can lead to a lot of PAs, all the while keeping your roster more stable in the process and not risking some pretty awful performances from replacement players, even if their scope of damage is limited to only a few plate appearances.